What is 'z' if the confidence interval is 80%?
1 Answer
Jan 28, 2017
Explanation:
Probability is 80% or 0.8
0.8 is evenly distributed on either side of z = 0
Find the nearest probability value or area in the table. It is 0.3997.
z value corresponding to 0.3997 is 1.28.
On the positive side we have 1.28 and negative side we have - 1.28
